Switch cover



K. HUNCIKER Aug. 15, 1933.

' SWITCH COVER I Filed Jan. 6, 1932 INVENTOR KARL HUNCIKER TORNEY Patented Aug. 15, 1933 UNITED STATES PATENT ()FFIQE SWITCH COVER Application January 6,

5 Claims.

This invention relates to thermostatic electric switches and more particularly to a cover therefor.

Thermostatically operated switches have been employed for a long time in electric circuits for 'various purposes such as operating dampers in domestic heating systems and for controlling the operation of domestic fluid fuel burners. When used in domestic heating systems of any character, the thermostatic switch is located in the room of the dwelling in which it is most desirable to maintain a uniform temperature and is usually located upon the wall where it is not only exposed to view but where a protection covering "is desirable.

The operation of such a switch is controlled by some means responsive to temperature changes, such as a coil of thermostatic metal, a bi-metallic coil, a capsule or bellows containing a fluid which expands or contracts in response to changes of temperature of the surrounding atmosphere. Since such operation is both adjustable and automatic, it is desirable to provide an instrument of this character which is very sensitive so that it may be adjusted to open or close the switch at a certain temperature in the room and will respond quickly. To produce this result when the ins'trument is protected by a casing or cover provision must be made in the cover to allow of as free a circulation of the surrounding air as possible and it is an object of this invention to provide a cover for such an instrument which will not only be pleasing to the eye but also so constructed as to provide a free'circulation of air therethro'ugh, thereby increasing the sensitiveness of operation.

With these and other objects in view reference is made to the accompanying sheet of drawing which illustrates an embodiment of this invention with the understanding that minor detail changes may be made without departing from the scope thereof.

In the drawing Figure 1 is a view in front elevation of a preferred form of this invention.

Figure 2 is a perspective view of Figure 1 with the front plate removed.

Figure 3 is a view in front elevation of the removed front plate.

Figure 4 is a transverse horizontal view in section taken on the line 44 of Figure 2, looking in the direction of the arrows illustrating one of the attaching means for the front plate.

Figure 5 is a top plan view of the front plate 1932. SerialNo. 585,021

preferably of thin metal, the front 1 of which is cut out and a spaced apart front plate 2 supported over the opening is made. If desired, an arcuate slot 3 may also be provided in the front 1 for the passage of the thermostat manual adjuster 4 and one edge of the slot sealed to indicate the temperature'at which the thermostat may be adjusted to operate; also, if desired, a thermometer 5 may be carried upon the front plate 2. In order to provide a circulation of atmospheric air through the casing or cover each side 6 of the cover is provided with a plurality of apertures 7 preferably of elongated form arranged close together and in a plurality of rows as shown in Figure 2 and while the top 8 of the 'casing or cover is preferably solid, it has been found desirable to provide the bottom 9 with a plurality of elongated aligned apertures 10 similar to those in each sidev The front 1 is shown as rectangular in shape and the cut ou. portion is preferably in the form of truncated triangles having its greatest width adjacent the bottom with its upper'edges brought together in an apex adjacent the top as shown in Figures 1 and 2 and the edges about the cut out portion are provided with uniform integral inturned angular flanges 11. The front plate 2 is of similar shape to the cut out portion but having the dimension between the free edges to the inturned flanges 11 and is supported over the cut out portion with the under surface of the plate 2 slightly above the plane of .the front 1 of the casing, as shown in Figure 6 with a uniform air space between its edges and the inturned flanges 11, as shown in Figure 1. The front plate 2 is preferably supported in this relation by providing a centrally notched member 12 formed integral with or secured to the free edges of the flanges 11 about the apex of the out out portion of the front 1 and extending in a plane parallel to the plane of the front adapted to receive with the notch 13 the annular groove 14 formed upon a stud 15 mounted upon the front plate 2 adjacent its illustrating the complementary attaching means. apex and by providing adjacent the bottom two oppositely disposed extensions from the flanges 11 of the body of the front 1 bent outward and then toward each other so that their outer surfaces are slightly above the plane of the front 1 to form ears 16, as shown in Figures 2 and 4, to which the front plate 2 may be secured in any desired manner, such as by small screws.

It has been found that by providing the openings 7 and 10 in the sides 6 and bottom 9 of the casing and the front plate 2 having the walls of the front 1 spaced apart therefrom and having the inturned angular flanges 11 thereabout, the atmospheric air as it becomes heated rises and enters the casing through the bottom apertures 10 and the front plate 2 is deflected by the flanges l1 and sets up a circulation of air therethrough and through the side apertures '7 so that temperature changes in the air of the room in which the thermostat is located are simultaneously transmitted to the temperature responsive switch operating mechanism within the thermostat casing or' cover.

It has beenfound in practice that not only does a casing of the type described decrease the differential of the operation of a thermostatic switch covered thereby, but also the supporting of the thermometer 5 upon the front plate 2 having a three pointconnection with the body of the front lessens the breaking of the thermometer by any torsional strains to which the cover may be subjected to during the course of assembly or transportation.

The advantage of providing a cover which will protect the switch mechanism and at the same time not interfere with the sensitiveness of its operation is obvious. As heretofore stated, the thermostatic switch when employed for controlling the temperature of dwellings is placed upon the wall approximately five feet from the floor and it is most desirable that the switch should operate immediately the temperature of the strata of air in the same plane with the switch reaches the temperature at which the switch is manually set to operate. It has been found that by perforating the bottom and sides of the cover and providing the elongated aperture in the front with the inturned flanges 11 and supporting the front plate 2 thereover in the manner described when the heated air ascends and enters through the bottom of the case, the flanges about the elongated opening in the front act as bafiies, so that the heated air passes out the apertures in the side walls of the case and in so doing sets up a circulation which causes an induction of the atmospheric air through the apertures about the front plate and the flanges about the front opening direct this incoming air toward the center of the cover, as shown by the arrows in Figure 6, and therefore directly upon the thermostatic element of the switch, so that the enclosing of the switch by this cover does not interfere with the sensitiveness of its action.

What I claim is:

1. A cover for a thermostatic switch having a series of openings in the sides and bottom thereof for atmospheric circulation and a large opening in the front with a front plate corresponding in shape to the front opening mounted with its under surface in the plane of the outer surface of the front and with its edges spaced apart from the edges of the front opening forming an additional means for atmospheric circulation.

2. A cover for a thermostatic switch having a series of openings in the sides and bottom thereof for atmospheric circulation and a large opening in the front with a front plate corresponding in shape to the front opening mounted with its under surface in the plane of the outer surface of the front and with its edges spaced apart from the edges of the front opening, forming an additional means for atmospheric circulation, the body of the front flanged about the front opening.

3. A cover for a thermostatic switch having a series of openings in the sides and bottom thereof for atmospheric circulation and a large opening in the front with a front plate corresponding in shape to the front opening mounted with its under surface in the plane of the outer surface of the front and with its edges spaced apart from the edges of the front opening, forming an additional means for atmospheric circulation, the body of the front flanged about the front opening away from the front plate.

4. A cover for a thermostatic switch having a series of'openings in the sides and bottom thereof for atmospheric circulation and a large opening in the front with a front plate corresponding in shape to the front opening mounted with its under surface in the plane of the outer surface of the front and with its edges spaced apart from the edges of the front opening, forming an additional means for atmospheric circulation, the body of the front flanged about the front opening away from the front plate and inclined in the direction of the interior of the cover forming a circulation bafiie or director plate.

5. A cover for a thermostatic switch having a series of openings in the sides and bottom thereof for atmospheric circulation anda large front opening away from the front plate and inclined at an angle approximating sixty degrees to the body of the front forming a circulation baffle or director plate.

KARL HUNCIKER. 

